The present invention relates to a permanent magnetic material and a bond magnet.
As conventional high performance rare earth permanent magnets such as Sm-Co-based and Nd-Fe-B-based magnets are known and the mass production thereof is under way. These magnets contain Fe or Co at high concentrations and they contribute to promotion in the level of the saturation magnetic flux density. These magnets also contain rare earth elements, and the rare earth elements bring about a very large magnetic anisotropy derived from the behavior of 4f electrons in the crystal field. As a result, the coersive force is increased, and a magnet of a high performance is realized. Such a high performance magnets are mainly used in electric appliances such as a loudspeaker, a motor, and a measuring device.
Recently, in order to meet the increasing demand for smaller electric appliances, a higher-performance permanent magnet by improving the maximum magnetic energy product is required.
On the other hand, Japanese Patent Application Laid Open (JP-A) No. 6-172936 discloses permanent magnetic material having a TbCu.sub.7 phase as the principal phase. The permanent magnetic material having a TbCu.sub.7 phase as the principal phase has excellent magnetic characteristics with a high saturation magnetic flux density. However, in the case an interstitial element such as H, N, C and P is contained in the above-mentioned permanent magnetic material, the magnetic characteristics greatly vary depending on the production conditions. The great variation of the magnetic characteristics results in a serious problem of the decline of the magnetic characteristics by offsetting the variation of the magnetic characteristics in the industrial mass production.